Switching question

[Mr Finster]

Hi all,

I apologise if this is a dumb question but I'm a complete noob when it comes to electronics.
  I have a little sound generator which I want to use as a carrier in a TX to TX passive ring modulator, It sounds pretty quirky as it is but obviously the plan is to switch the carrier on and off to match the duration of the incoming external audio by using the incoming audio. Is there a really simple way of doing this or am I looking at something like injecting DC to bias both audio signals above the minimum base voltage for a transistor and then decoupling with a cap to strip the DC off before entering the ring mod?

Thanks in advance.